Richard Cushworth, and his wife, Mercedes Casanellas welcomed a son at a hospital in San Salvador in May this year, but say they immediately suspected that something was wrong.

The couple, who live in Dallas, Texas, have since had a DNA test and found that the child handed to them by hospital staff is not related to either of them.

Investigators tracked down the child by ordering other new mothers to have their babies DNA tested.

The parents of four other boys who were also born on the same day, May 21, had last week brought their babies to be DNA tested last week after an order was issued by the country's Prosecutor General's Office, which had taken over the investigation.

The baby whose tests were last to be processed proved to be the couple's real child.

Speaking last night, Prosecutor General Luis Martinez said that the babies of the two couples had been mixed up and that each would be returned to their rightful parents at a special court hearing with the presence of a judge.